Milder winters and the presence of certain diseases in 2016 is leaving the potential for issues in winter wheat crops this year. To ensure you know what to look for in your region, we have gathered information on the two main diseases and offer possible solutions to help you get the most out of your crop.
Stripe rust, also known as yellow rust, favours mild winters and cool, wet summers for development. Typically, the disease blows in with wind currents from the Pacific Northwest to infect crops in Southern Alberta. With milder winters in recent years, the disease has been known to overwinter. In these situations, the mycelium have the ability to remain viable to minus 5 degrees Celsius allowing for early infection to occur.
The disease typically follows the highway 2 corridor in Alberta, but in 2015, was found as far north as Beaverlodge, indicating the disease overwintered in the Peace Region. In the same year, stripe rust was found in Northern Saskatchewan, showing us its potential to travel with wind currents.
Dr. Kequan Xi and Krisham Kumar from Alberta Agriculture’s Lacombe Research Centre surveyed fields in the fall of 2016 and found an infection level of one per cent in the Camrose region, no rust in the Lacombe region, and one to 11 percent infection in the Olds region.
Routine scouting is key to determining the level of infection in individual fields. Fungicide may be warranted if infection is found, but growing resistant varieties (Wildfire has full resistance and Moats, Emerson, Chase, and Gateway have moderate resistance) and breaking the “green bridge” are other important management strategies. Click here for more about breaking the green bridge.
Wheat Streak Mosaic Virus
Wheat Streak Mosaic Virus (WSMV) is a disease primarily found in wheat that can be transmitted by wheat curl mites. Mites can be blown from field to field by the wind and can overwinter on winter wheat.
Dr. Mike Harding from Alberta Agriculture’s Crop Diversification Centre in Brooks, surveyed 20 fields for WSMV in 2015 and 20 fields in 2016. In the 2016 survey, 14 out of 20 fields tested positive for WSMV, making us more aware of the disease this season.
WSMV can cause stunted growth, lower seed production and may not form seed heads in wheat plants and can be identified by dashes, streaks, and yellow stripes on leaves parallel to the veins. If plants are infected during the early tillering stage, the plant will stop growing and produce few to no heads.
It is best to be proactive, and because the disease was present last year, we recommend growers be vigilant in monitoring their spring and winter wheat crops this year.
The best management practice for controlling WSMV is by controlling the green bridge. If seeding spring wheat into winter wheat stubble, be sure to control volunteer winter wheat prior to seeding.
If you are concerned about WSMV in your region, plant a winter wheat variety such as Radiant or Elevate as both are resistant to the WSMV mite.